Objective To predict and analyze the structure and function of Stenotrophomonas maltophilia OmpA. Methods Bioinformatics software and biological databases were used to analyze the physicochemical properties, signal peptides,and transmembrane structures of the OmpA protein and to predict the subcellular localization, secondary and tertiary structures,sequence homology and conserved domains,and epitopes of OmpA.Results OmpA protein had strong hydrophilicity but without transmembrane helices in mature protein,and positions 1-22 of the sequence were predicted as signal peptide.In the second structure random coil helix,αlpha-helix,beta-turn and extended strand made up 50.27%, 24.59%,9.29%and 15.85%,respectively.The three-dimensional structure was β-barrel.OmpA was highly conserved among S.maltophilia strains but shared minimal homology with human and mouse proteins.The N-terminal domain of OmpA was OM-channels superfamily and the C-terminal domain of OmpA was OmpA_C-like superfamily.OmpA protein contained 11 dominant antigen epitopes.Conclusion The characteristics of OmpA identified by bioinformatics analysis can not only provide reference for the study of the structure and novel function of OmpA,but also theoretically contribute to the research on related new subunit vaccines.